Intel’s Core i5-655K & i7-875K Unlocked Processors

Most of today’s desktop CPUs, including budget models, tend to be good for overclocking. But for those who are looking for the ultimate in tweaking ability, Intel’s mainstream models have left a bit to be desired. With the K series, though, it aims to remedy that situation by offering unlocked models at affordable prices.

System: Sandra Memory, Multi-Core Efficiency

Generally speaking, the faster the processor, the higher the system-wide bandwidth and the lower the latency. As is always the case, faster is better when it comes to processors, as we’ll see below. But with Core i7, the game changes up a bit.

Whereas previous memory controllers utilized a dual-channel operation, Intel threw that out the window to introduce triple-channel, which we talked a lot about at August’s IDF. Further, since Intel integrates the IMC onto the die of the new CPUs, benefits are going to be seen all-around.

Before jumping into the results, we already had an idea of what to expect, and just as we did, the results seen are nothing short of staggering.

As Clarkdale’s microarchitecture changed where the IMC is located, the speed in bandwidth and latencies has been decreased ever-so-slightly with the Core i5-655K. The Core i7-875K performs very well, near the top of the charts.

Thanks again to BIOS improvements, the Core i5-655K sees nice gains over the Core i5-661, which again was benchmarked long ago with an older BIOS. The Core i7-875K on the other hand performed near-identically to the Core i7-870, which is what we expected given their stark similarities.

Sandra 2009 Multi-Core Efficiency

How fast can one core swap data with another? It might not seem that important, but it definitely is if you are dealing with a true multi-threaded application. The faster data can be swapped around, the faster it’s going to be finished, so overall, inter-core speeds are important in every regard.

Even without looking at the data, we know that Core i7 is going to excel here, for a few different reasons. The main is the fact that this is Intel’s first native Quad-Core. Rather than have two Dual-Core dies placed beside each other, i7 was built to place four cores together, so that in itself improves things. Past that, the ultra-fast QPI bus likely also has something to do with speed increases.